Containers coated by deposition of a sol-gel on their inner surface

ABSTRACT

The present invention relates to containers having, on all or part of their inner surface, a mineral-oxide-based coating obtained by sol-gel deposition, which containers are found to be particularly suitable for the packaging of cosmetic compositions.

The present invention relates to containers provided with a coating ontheir inner surface, which containers are suitable especially for thepackaging of cosmetic compositions, especially liquid compositions orcompositions in gel form. The invention more specifically relates tocontainers of that type having e transparent body and wherein the innercoating comprises a colouring agent and/or an agent that absorbsultraviolet radiations.

The term “container”, as used herein, denotes any device suitable forcontaining, inter alia, a liquid composition. Typically, a containerwithin the scope of the present description is a vial, a bottle, a jar,a tube, a round bottle or a canister. More generally, it can be anyarticle for packaging cosmetics.

When a container is completely filled with a liquid, only part of itssurface is in contact with said liquid. Within the scope of the presentdescription, the “inner surface” of the container denotes the part ofthe surface of the container that is in contact with the liquid when thecontainer is completely filled. By contrast, the remainder of thesurface of the container, which is not in contact with the liquid whenthe container is filled completely, is referred to as the “externalsurface”.

Furthermore, the volume of the container that is filled with liquid whenthe container is full is referred to as the “inner cavity” of thecontainer.

Various types of container that are coated on all or part of theirsurface, especially for the purpose of aesthetic decoration, labeling orprotection, are known at the present time.

Most of the time, such coatings are applied to all or part of theexternal surface of the containers (typically by the deposition ofpaints, inks, polymers or varnishes), the deposition of which on thecontainer generally does not present any specific technical problems.

Especially in the field of cosmetics packaging, a different, morespecific type of coating is desired, namely a coating provided on all orpart of the inner surface of the containers.

Inner coatings of that type are found to be particularly valuable whenthe body of the container is transparent and reveals the deposited innercoating (for example when the container is made of glass or plastics).In particular, coloured inner coatings deposited on the surface oftransparent vials provide an interesting aesthetic effect, with a deptheffect of the colouring applied to the inner coating contrasting withthe thickness of the vial, that effect generally being more pronouncedwhen the vial has facets and the thicker its walls.

Containers provided with coloured inner coatings of the above-mentionedtype have been proposed, especially for packaging perfumes.Nevertheless, within that context, only the disclosures relate to thedeposition of inner coatings that do not permit direct contact with acosmetic composition.

More precisely, it has been proposed to colour the inner surface ofperfume vials by lacquering, typically by depositing coloured varnishesor paints. A problem is that the colouring agents present in thecoloured coatings deposited by lacquering tend to migrate to thecosmetic compositions with which they are in contact, especially whenthe compositions are alcoholic compositions such as perfumes. This canlead in the very short term to unacceptable colouring of the cosmeticcomposition and/or to a loss of the colouring of the inner coating,which is also disadvantageous.

Therefore, with containers provided with coloured inner coatings of theabove-mentioned type, the cosmetic composition cannot be contained assuch in the container. The packaging of a cosmetic composition in suchcontainers has certainly been described but, in that specific case, notthe composition itself is contained in the container but a flexiblecontainer, such as plastics pocket, which protects the composition. Inthat case, the packaging of the cosmetic composition in the intermediateflexible container allows avoiding any contact between the cosmeticcomposition and the inner coating.

The instant invention aims at providing a novel type of container thatis coated on its inner surface by a coating layer which can be colouredand which is further suitable for the direct packaging of a cosmeticcomposition without having to inhibit contact between the cosmeticcomposition and the coating layer.

To that end, according to a first aspect, one object of the invention isa container having, on all or part of its inner surface, amineral-oxide-based coating obtained by a sol-gel process.

The term “sol-gel process” is here to be understood in its broad meaningand denotes a process of known type wherein a medium comprising at leastone mineral alkoxide precursor (in most cases an alkoxide of formulaM(OR)_(n) wherein M denotes silicon or a metal such as Al or Ti; ndenotes the valence of the element M; and the n groups —OR are identicalor different organic groups, for example alkoxy groups) is hydrolysed.As it hydrolyses, the precursor of the alkoxide type used in a sol-gelprocess is converted into hydroxylated species (typically of formulaM(OH)_(n) wherein M and n have the meanings given hereinbefore) whichcondense together to form mineral oxide particles by a process which iscomparable to a polymerisation of the mineral precursor. Typically,those hydrolysis and condensation reactions first yield a sol(suspension of oxide particles) which gradually becomes concentrated,the particles that are forming occupying an ever larger volume fraction,whereby a gel is obtained; hence the generic expression “sol-gel” givento processes of this type.

A coating obtained by a sol-gel process, of the type that is applied tothe inner surface of a container according to the present invention, isobtained by depositing a gel as obtained by the process describedhereinbefore and then drying the gel. The deposition of the gel on thesurface on which coating is to be carried out can be obtained either bypreparing the gel under the above-mentioned conditions and then applyingit to the surface, or by applying to the surface to be treated acomposition comprising the mineral precursor in the partially hydrolysedstate only (for example in the sol state) and then allowing gelling ofthe medium to take place only in the deposit so made (this second modeof operation allowing the deposition of a coating of more controlledthickness, especially in the form of thin films). In order to strengthenthe deposit obtained after drying of the solvent, it can be of interestto subject the dried deposit obtained after evaporation of the solventto heat treatment, in a so-called “annealing” step. It is to be notedthat coatings (deposits) produced by the sol-gel technique do notrequire the use of high temperatures (the hydrolysis-condensationreactions that yield the gel can typically be carried out at ambienttemperature and the optional annealing step generally does not requiretemperatures above 200° C. and can typically be carried out attemperatures of from 70 to 200° C., for example from 80 to 180° C.).

For further details regarding sol-gel processes and the production ofcoatings by that technique, reference may be made especially to thedocuments described below:

-   -   Observatoire Francais des Techniques Avancées, Matériaux        Hybrides, 1996    -   G. Schottner, J. Kron, K. J. Deichmann, VERRE, 2000, 6, 5    -   P. G. Parejo, M. Zayat, D. Levy, J. Mater. Chem., 2006, 16,        2165-2169    -   M. Zayat, D. Levy, J. Mater. Chem. 2003, 13, 727-730    -   R. Pardo, M. Zayat, D. Levy, J. Mater. Chem. 2005, 15, 703-708    -   K. Wojtach, K. Cholewa-Kowalska, M. Laczka, Z. Olejniczak,        Optical Materials, 2005, 27, 1495-1500    -   J. Kron, G. Schottner, K. J. Deichmann, Thin Solid Films, 2001,        392, 236-242    -   K. H. Haas, S. Amberg-Schwab, K. Rose, Thin Solid Films, 1999,        351, 198-203    -   K. Wojtach, M. Laczka, K. Cholewa-Kowalska, Z. Olejniczak, J.        Sokolowska, J. Non-Cryst. Sol., 2007, 353, 2099-2103    -   J. L. Almaral-Sanchez, E. Rubio, J. A. Calderon-Guillen, A.        Mendoza-Galvan, J. F. Perez-Robles, R. Ramirez-Bon, Azojomo,        2006, 2    -   Y. Castro, A. Duran, R. Moreno, B. Ferrari, Advanced Materials,        2002, 14, n° 7    -   H. M. Shang, Y. Wang, S. J. Limmer, T. P. Chou, K.        Takahashi, G. Z. Cao, Thin Solid Films, 2005, 472, 37-43    -   G. D. Kim, D. A. Lee, J. W. Moon, J. D. Kim, J. A. Park, Appl.        Organometal. Chem. 1999,13, 361-372    -   J. P. Boilot, F. Chaput, T. Gacoin, VERRE, 2000, 6, n° 5    -   Z. Chan, L. Ai 'mei, Z. Xiao, F. Miao, H. Juan, Z. Hongbing,        Optical Materials, 2007, 29, 1543-1547    -   thesis of Melle Nathalie Landraud, Nanostructuration optique de        films sol-gel photochromiques par microscopie en champ proche,        October 2002.

The coatings deposited on the inner surface of a container according tothe invention can be prepared by any process of the prior art known perse. It is generally preferred for the deposited coating to be obtainedby acid hydrolysis of a mineral oxide of the above-mentioned formulaM(OR)_(n). Alternatively, it is, however, also possible for the coatingdeposited according to the invention to be obtained by hydrolysis of amineral alkoxide in a basic medium.

The sol-gel coating present on the inner surface of a containeraccording to the invention generally has a thickness ranging fromseveral nanometres to several hundred micrometres, the thicknesspreferably being from 100 nm to 500 microns and more preferably from 40microns to 300 microns.

Advantageously, the coating present on the inner surface of a containeraccording to the invention is obtained by a sol-gel process using asmineral precursor at least one silicon alkoxide, whereby the sol-geldeposit formed comprises a matrix based on a silica network, which isbroadly similar to a glass having controlled porosity. According to thisembodiment, the silicon alkoxide used advantageously has the followingformula (I):

Si(OR)₃R′  (I)

wherein:

-   -   each of the three groups R, which are identical or different        (preferably identical), is an alkyl group, typically a methyl or        ethyl group (the three groups OR generally being identical); and    -   R′ is an alkoxy group identical with or different from the 3        groups (OR) mentioned above; or alternatively a different        organic group.

The coatings of the sol-gel type which can be used according to thepresent invention, in particular those obtained from precursors of thesilicon alkoxide type, have the advantage that they can be applied to alarge number of materials, especially to glass or metal, oralternatively to other materials, such as plastics.

Another advantage of the sol-gel coatings of the invention is that theirproperties can readily be modulated as a function of the intendedapplication of the coating.

To that end, it should first be emphasised that coatings produced by thesol-gel technique are in the form of crosslinked mineral oxide matriceswherein different species (particles, polymers, molecules of large size)can be trapped, which can be used to modify the physicochemicalproperties of the coating. In order to trap such species within thecoating, the species must simply be introduced into the medium forforming the sol, the species thereby ultimately being trapped in the geland then in the solid matrix obtained after drying of the gel.

In addition, according to the sol-gel technique, it is possible in avery simple manner to obtain coatings that are functionalised byspecific functional groups which are bonded, advantageously covalently,to the coating. Such functionalisation of the coating can especially beobtained by making use, as starting materials mineral precursorscarrying desired functional groups (for example by using precursors ofthe above-mentioned formula (I) wherein R is a functional group of thedesired type).

These various possibilities, in conjunction with the fact that thedeposition of a coating by the sol-gel technique can be carried out atvery low temperatures, allow a great modularity for the coatedcontainers according to the invention. The invention accordingly permitsaccess to a wide range of containers suitable for very manyapplications.

In a container according to the invention, the coating present on theinner surface in most cases comprises macromolecular species (organic orinorganic particles or polymers) which are trapped within itsmineral-oxide-based structure and/or is functionalised by functionalgroups bonded, preferably covalently, to said coating. Within thiscontext, the coating present on the inner surface of a containeraccording to the invention is preferably a hybrid organic/inorganiccrosslinked network comprising organic species dispersed in themineral-oxide-based structure and/or bonded to said structure.

In this scope, according to a first interesting embodiment of theinvention, the coated container according to the invention has atransparent body and the coating present on the inner surface of thetransparent container is a coating which is coloured or has a visualappearance which is different from that of the body of the container,and which is visible through the body of the container. The expression“body of the container” is here understood as meaning the part thatconstitutes the container, separate from the coating. According to thisembodiment, the body of the container is advantageously made of glass.

The containers according to this first embodiment of the inventive showan interesting aesthetic effect, the inner layer being visible throughthe body of the container, which confers thereon an appearance which iscoloured or decorated in depth, such an appearance being especiallyprized and sought-after notably in the cosmetics packaging. Within thescope of the invention, contrary to the techniques proposed hitherto forobtaining such a decorative effect, the cosmetic composition can bebrought directly into contact with the inner coating of the container.

According to the first embodiment of the invention, the coating presenton the inner surface of the container can be a coating of thetranslucent or transparent type, suitable for revealing a cosmeticcomposition contained in the container or, on the other hand, it can bean opaque coating which conceals the composition. Within this context,coatings of the opaque type are found to be generally of interest,especially insofar as they confer on the container a deeply coloured ordecorated appearance which is particularly pronounced.

The coating present on the inner surface of a container according to thefirst embodiment of the invention can advantageously comprise:

-   -   at least one colouring agent bonded, preferably covalently, to        the mineral oxide matrix of the coating, and/or    -   particles based on coloured pigment and/or particles that modify        the light absorption, reflection or refraction properties, said        particles being trapped within the mineral-oxide-based structure        of the coating.

According to a first variant of the first embodiment of the invention,the coating present on the inner surface of the container comprises acolouring agent which is fixed to the surface of the coating by way of acovalent bond.

Within the scope of the present description, the expression “colouringagent” is understood as meaning a compound that absorbs and/or emitsradiation in the visible range. The term includes especiallyconventional colouring agents, which absorb radiation in the visiblerange, as well as fluorescent or phosphorescent compounds, which emit avisible light when they are excited.

A method of interest for obtaining according to the invention, a coatingcomprising covalently bonded colouring agents of the above-mentionedtype comprises preparing the coating by the sol-gel technique using oneor more mineral precursors including a mineral precursor to which saidcolouring agent is bonded covalently. Especially, a coating comprisingcolouring agents bonded covalently to its surface can be obtained bycarrying out the following steps:

(A1)) a colouring agent carrying a reactive functional group R^(r) isreacted with a silicon alkoxide having the following formula (I¹):

Si(OR)₃R^(c)   (I¹)

wherein:

-   -   each of the groups R, which may be identical or different, is an        alkyl group, typically a methyl or ethyl group (the three groups        OR generally being identical); and    -   R^(c) is a functional group complementary to the reactive        functional group R^(r) carried by the colouring agent, which        reacts with that functional group to form a covalent bond        between the colouring agent and the silicon alkoxide, whereby        there is formed a silicon alkoxide having the above-mentioned        formula (I):

Si(OR)₃R′  (I),

wherein R has the meaning given hereinbefore and wherein R′ is a groupresulting from the reaction of the functional group R^(c) with thecolouring agent carrying the reactive functional group R^(r); then(B1) the sol-gel deposition is carried out on the inner surface of thecontainer using as mineral precursor the silicon alkoxide (I) obtainedin step (A1), preferably in association with a silicon alkoxide offormula Si(OR″)₄ wherein each of the groups R″, which may be identicalor different, denotes an alkyl group, preferably an alkyl or a methyl.

According to this variant, the functional group R^(r) carried by thecolouring agent can typically be a hydroxyl functional group —OH, thefunctional group R^(c) carried by the silicon alkoxide (I¹) thenpreferably being an isocyanate functional group —C═N═O, these twofunctional groups reacting to form a carbamate covalent bond between thesilicon alkoxide and the colouring agent, according to the followingreaction scheme:

[alkoxide]—CNO+[colouring agent]—OH→alkoxide—CNH—COO—[colouring agent].

A silicon alkoxide carrying an isocyanate functional group which is verysuitable in this context is 3-isocyanatopropyltriethoxysilane, offormula (C₂H_(S)O)₃Si—(CH)₃—NCO, also known by the acronym ICPTEOS. Manycolouring agents carry —OH functional groups and can be used conjointlywith ICPTEOS or other silicon alkoxides carrying an isocyanatefunctional group, among which there may be mentioned, for example, thefollowing colouring agents: the colouring agent red 1, especially in theform DR1 (dispersed red 1) or alternatively the colouring agents solventviolet 13, solvent blue 90 or solvent yellow 82, as well as purpurin,anthrapurpurin or alizarin.

More generally, the functional groups R^(r) and R^(c) carried,respectively, by the colouring agent and the silicon alkoxide (I¹) usedin step (A1) can be selected from any pair of functional groups suitablefor forming a covalent bond. Within this context, and without implyingany limitation, the functional groups R^(r) and R^(c) may be selectedespecially as follows:

R^(r)=—OH and R^(c)=—C═N═O; or

R^(r)=—NH2 and R^(c)=—COOH.

In step (B1), the coating obtained by the sol-gel technique ispreferably produced using, as mineral precursor, a mixture of thesilicon alkoxide of formula (I) as obtained following step (A1) with asilicon alkoxide having the above-mentioned formula Si(OR″)₄, preferablyin a molar ratio alkoxide (I)/Si(OR″)₄ of from 10% to 50%,advantageously from 25% to 35%. In step (B1), TEOS (tetraethoxysilane offormula Si(OC₂H₅)₄) is preferably used as the alkoxide of formulaSi(OR″)₄.

According to a second variant of the first embodiment of the invention,the coating present on the inner surface of the container comprisesparticles that modify the light absorption, reflection or refractionproperties, which particles are trapped within the mineral-oxide-basedstructure of the coating. Where applicable, those particles, which areisotropic or anisotropic, typically have sizes ranging from 10 to 500microns, more preferably from 20 to 400 microns.

The particles present in the coating according to this second particularvariant can especially comprise:

-   -   coloured pigment particles; and/or    -   mother-of-pearl particles (which are able to confer a reflective        effect on the inner coating); and/or    -   metallic particles (which are able to confer a metallic        reflective effect on the inner coating).

Coatings comprising particles of the above-mentioned type are typicallyobtained by preparing the coating by the above-mentioned sol-geltechnique and introducing into the medium for forming the gel from themineral precursor the particles which are ultimately to be incorporatedin the inner coating deposited on the inner surface of the containeraccording to the invention.

According to a second embodiment of the invention (which is compatiblewith the preceding embodiment), the coated container according to theinvention has a transparent body, and the coating present on the innersurface of the transparent container comprises a compound that absorbsradiation in the ultraviolet range (that is to say an ultraviolet filteralso called anti-ultraviolet filter) which is covalently bonded to saidcoating. According to this embodiment, the body of the container isadvantageously made of glass. The presence of an anti-ultraviolet filterin the coating according to the second embodiment of the invention makesit possible to protect the cosmetic composition contained in thecontainer, the properties of which might otherwise be affected when thecontainer is exposed to radiation in the ultraviolet range, for examplewhen the container is exposed to sunlight. Containers according to thisembodiment accordingly enable a protective effect to be provided for thecompositions they contain.

The anti-ultraviolet filters used in the second embodiment of theinvention can be selected, for example, from the benzophenones oralternatively from the benzotriazoles.

Coatings comprising anti-ultraviolet filters of the above-mentioned typebonded covalently to said coating can be prepared especially by usingthe sol-gel technique and employing one or more mineral precursorsincluding a mineral precursor to which there is bonded covalently acompound that absorbs in the ultraviolet range.

Especially, a coating comprising anti-ultraviolet filters bondedcovalently to its surface can be obtained by carrying out the followingsteps:

(A2) a compound that absorbs radiation in the ultraviolet range andcarrying a reactive functional group R′ is reacted with a siliconalkoxide having the following formula (I²):

Si(OR)₃R^(c)   (I²)

wherein:

-   -   each of the groups R, which may be identical or different, is an        alkyl group, typically a methyl or ethyl group (the three groups        OR generally being identical); and    -   R^(c) is a functional group complementary to the reactive        functional group    -   R^(r) carried by the compound that absorbs radiation in the        ultraviolet range, which reacts with that functional group to        form a covalent bond between the compound that absorbs in the        ultraviolet range and the silicon alkoxide, whereby there is        formed a silicon alkoxide having the above-mentioned formula        (I):

Si(OR)₃R′  (I),

wherein R has the meaning given hereinbefore and wherein R′ is a groupresulting from the reaction of the functional group R^(c) with thecompound that absorbs in the ultraviolet range and carrying the reactivefunctional group R^(r); then(B2) the sol-gel coating is carried out on the inner surface of thecontainer using as mineral precursor the silicon alkoxide (I) obtainedin step (A2), preferably in association with a silicon alkoxide offormula Si(OR″)₄wherein each of the groups R″, which may be identical or different,denotes an alkyl group, preferably an alkyl or a methyl.

According to this variant, steps (A2) and (B2) are preferably carriedout under the preferred conditions defined for steps (A1) and (B1)employed within the scope of the first variant of the first particularembodiment of the present invention. In particular, the functional groupR^(r) carried by the compound that absorbs in the ultraviolet range cantypically be a hydroxyl functional group —OH, the functional group R^(c)carried by the silicon alkoxide (I¹) then preferably being an isocyanatefunctional group —C═N═O, those two functional groups reacting to form acarbamate covalent bond between the silicon alkoxide and the compoundthat absorbs in the ultraviolet range.

In that case too, a silicon alkoxide carrying an isocyanate functionthat is highly suitable within this context is3-isocyanatopropyltriethoxysilane, having the formula(C₂H_(S)O)₃Si—(CH)₃—NCO) (ICPTEOS mentioned hereinbefore).

In addition, in step (B2), the coating obtained by the sol-gel techniqueis preferably formed using, as mineral precursor, a mixture of thesilicon alkoxide of formula (I) as obtained following step (A2) with asilicon alkoxide having the formula Si(OR″)₄, that additional alkoxidepreferably being TEOS (tetraethoxysilane of formula Si (OC₂H₅)₄).

Whatever the nature of the inner coating present on the inner surface ofa container according to the invention, the coating can be produced byany process known per se for producing a coating of that type. Forcontainers having a wide opening (for example a wide-necked jar), themajority of the known techniques can generally be used, especially spraycoating techniques. More generally, it is also possible to use the knownspin coating methods or alternatively dip-coating, flow-coating andcapillary coating methods.

For containers having a narrow neck or, more generally, for containershaving undercut surfaces (that is to say containers which cannot bemoulded in one piece, such as bottles or vials), more specifictechniques are to be used. For such containers, the inner coating cantypically be produced by a spin coating technique. Within this context,the gelled material obtained from the mineral precursor (or a more fluidmedium obtained by only partial hydrolysis of the mineral precursor) ispreferably deposited in the container and the container is subjected toa circular movement according to one of its axes so that the compositionthat has been introduced is deposited on the inner surface of thecontainer. Another technique which can be used is spray coating, inwhich an injection nozzle is introduced into the container, throughwhich the gelled material obtained from the mineral precursor (or a morefluid medium obtained by only partial hydrolysis of the mineralprecursor) is projected onto the inner surface of the container. Suchspin coating and spray coating techniques are highly suitable forproducing an inner coating on any type of container, whatever its shape.

As emphasised hereinbefore in the present description, the containersaccording to the present invention are particularly suitable for thepackaging of cosmetic compositions, where they permit direct contactbetween the inner coating and the cosmetic composition. According toanother aspect, this particular use of the containers of the inventionconstitutes another particular object of the present invention.

Within this context, the container according to the invention ispreferably a vial or a bottle, preferably made of glass. When the termglass is used in the present description, it preferably refers to adihizocalcic, sodocalcic or borosilicate glass, preferably to a glass oftype III, especially of the type conventionally used to constituteperfume vials. Alternatively, monosilate glasses can be used.

The containers of the invention are especially suitable for thepackaging of cosmetic compositions in the form of liquids (perfumes,oils, lotions, etc.), but they are also suitable for the packaging ofother types of cosmetic formulations, including especially gels, creams,or alternatively compositions in powder form. The containers of theinvention are used in particular in the packaging of water- oralcohol-based cosmetic compositions and they are advantageously employedto contain perfumes or alternatively milks, creams, gels, pastes and,more generally, any other cosmetic product.

Various aspects and advantages of the invention are further described inthe illustrative examples described hereinbelow, wherein sol/gelcoatings have been produced on the inner surface of vials made ofsodocalcic and borosilicate glass.

EXAMPLE 1

Deposition of a Sol-Gel Film Prepared from TEOS

In a first example, a sol-gel coating was deposited on the inner surfaceof a vial, the sol-gel coating being obtained by hydrolysis oftetraethoxysilane TEOS.

2 ml of TEOS and then 0.5 ml of ethanol were introduced into a beaker,and the mixture was stirred for one minute. A hydrochloric acid solutionobtained by adding one drop of 35% HCl to 0.5 ml of distilled water wasadded dropwise, with stirring, to the mixture so obtained.

When the addition of acid was complete, the mixture was stirred for afurther 24 hours.

A silica gel was thus obtained.

That gel was used to cover the inner surface of a vial which hadpreviously been cleaned in an ethanol bath and then rinsed with water.To that end, the gel was deposited on the inner surface of the vial byspin coating; the resulting film was then dried for 5 minutes and wasdried for two hours at 160° C. It is to be noted that deposition canalso be carried out by spray coating techniques or alternatively by spincoating, dip coating, flow coating and capillary coating.

EXAMPLE 2

Deposition of a Sol-Gel Film Obtained from a Mixture of PrecursorsTEOS+PhTES+GPTES

In the example, a gel was produced from three different silanes, namelyTEOS as used in Example 1, PhTES (phenyltriethoxysilane) and GPTES(3-(glycidylpropyl)-triethoxysilane).

The gel was prepared under the following conditions:

0.2 ml of TEOS, 0.34 ml of GPTES and 0.5 ml of PhTES were introducedinto a beaker, then 5.25 ml of ethanol were introduced into the mixtureso formed.

An HCl solution obtained by adding one drop of 35% HCl to 0.2 ml ofdistilled water was then introduced dropwise into that mixture, atambient temperature (25° C.) and with stirring. When the addition wascomplete, the mixture was stirred for a further 5 minutes. One drop of a20% ammonia solution and a Microlith pigment (pigment marketed by CIBA)were then introduced, and stirring was continued for a further 10minutes.

The resulting gel was used to cover the inner surface of a vial whichhad previously been cleaned in an ethanol bath and then rinsed withwater. To that end, the gel was deposited on the inner surface of thevial by spin coating and then the resulting film was dried for two daysand was heat treated at 160° C. for 2 hours.

EXAMPLE 3 Deposition of a Sol-Gel Film Comprising a Colouring Agent

In this example, a coating comprising a colouring agent (colouring agentred DR1 “dispersed red 1”) was produced on the inner surface of a vialmade of glass.

To that end, the following protocol was carried out.

In a 100 ml wide-necked pill-making machine, 1.24 ml of ICPTEOS werereacted for 24 hours at 70° C. with 145 mg of DR1 in 21.1 ml ofpyridine, under an inert N₂ atmosphere and with stirring.

The resulting mixture was cooled to ambient temperature (25° C.), andthen 3.8 ml of TEOS (tetraethoxysilane Si(OC₂H₅)₄) and 25.3 ml ofethanol were added, with stirring.

The mixture so produced was stirred for a further 10 minutes.

An HCl solution obtained by mixing 11 microlitres of a 35% HCl solution(11 M) and 1.5 ml of distilled water was then introduced dropwise intothe mixture, at ambient temperature (25° C.) and with continuedstirring. When the addition was complete, stirring was continued for 45minutes, whereby a gel including the colouring agent DR1 bondedcovalently to the synthesised silica was obtained.

The resulting gel was used to cover the inner surface of a vial whichhad previously been cleaned in an ethanol bath and then rinsed withwater. To that end, the gel was deposited on the inner surface of thevial by spin coating, and the resulting film was then dried for 2 hoursat 80° C.

EXAMPLE 4 Deposition of a Sol-Gel Film Comprising a UV Absorber(Benzophenone)

In this example, a coating comprising an anti-UV filter was produced onthe inner surface of a vial made of glass, according to the followingprotocol.

In a 100 ml wide-necked pill-making machine, 1.24 ml of ICPTEOS(3-isocyanato-propyltriethoxysilane of formula (C₂H_(S)O)₃Si—(CH)₃—NCO)were reacted for 24 hours at 70° C. with 0.4 g of2-hydroxy-4-methoxybenzophenone in 21.1 ml of pyridine, under an inertN₂ atmosphere and with stirring.

The resulting mixture was cooled to ambient temperature (25° C.), andthen 3.8 ml of TEOS (tetraethoxysilane Si(OC₂H₅)₄) and 25.3 ml ofethanol were added, with stirring.

The mixture so produced was stirred for a further 10 minutes.

An HCl solution obtained by mixing 11 microlitres of a 35% HCl solution(11 M) and 1.5 ml of distilled water was then introduced dropwise intothe mixture, at ambient temperature (25° C.) and with continuedstirring. When the addition was complete, stirring was continued for 45minutes, whereby a gel including benzophenone bonded covalently to thesynthesised silica was obtained.

The resulting gel was used to cover the inner surface of a vial whichhad previously been cleaned in an ethanol bath and then rinsed withwater. To that end, the gel was deposited on the inner surface of thevial by spin coating, and the resulting film was then dried for 2 hoursat 80° C.

1. A container comprising: a body, and on all or part an inner surfaceof the body, a mineral-oxide-based coating; wherein themineral-oxide-based coating is obtained by sol-gel deposition.
 2. Thecontainer according to claim 1, wherein the the sol-gel depositioncomprises a mineral precursor of at least one silicon alkoxide havingthe formula:Si(OR)₃R′  (I) wherein: each R, is independently, an alkyl group; and R′is an alkoxy group which may be identical to OR, different from OR; or adifferent organic group.
 3. The container according to claim 1, whereinon the inner surface coating comprises macromolecular species trappedwithin a mineral-oxide-based structure and/or the coating isfunctionalised by functional groups bonded covalently to the coating. 4.The container according to claim 1, wherein the body is transparent, andthe coating on the inner surface is a colored or has a visual appearancedifferent from that of the body, and is visible through the body of thecontainer.
 5. The container according to claim 4, wherein a coloringagent is covalently bonded to a surface of the coating.
 6. The containeraccording to claim 5, wherein the coating on the inner surface of thecontainer is obtained by a method comprising: (A1) reacting a coloringagent having a reactive functional group R^(r) with a silicon alkoxideof formula (I¹):Si(OR)3R^(C)   (I¹) wherein: each R, independently, is an alkyl group;and R^(C) is a functional group which reacts with the functional groupR^(r) to form a covalent bond between the coloring agent and the siliconalkoxide, whereby the silicon alkoxide of formula (I) is obtained:Si(OR)3R′  (I), wherein R is as previously defined and R′ is a groupresulting from the reaction of the functional group R^(c) with the R^(r)functional group of the coloring agent; and then (B1) sol-gel coatingthe inner surface of the container with the silicon alkoxide mineralprecursor (I) obtained in (A1), optionally in association with a siliconalkoxide of formulaSi(OR″)⁴ wherein each R″, is, independently, an alkyl group.
 7. Thecontainer according to claim 6, wherein R^(r) is —OH and R^(c) is—C═N═O, and the silicon alkoxide (I¹) is3-isocyanatopropyltriethoxy-silane; (CH₂H₅O)₃Si—(CH)₃—NCO.
 8. Thecontainer according to claim 6, wherein, in (B1), the sol-gel coatingcomprises a mixture of the silicon alkoxide of formula (I) andtetraethoxysilane.
 9. The container according to claim 4, wherein thecoating on the inner surface comprises particles trapped within themineral- oxide-based structure of the coating that modify lightabsorption, reflection or refraction properties of the coating.
 10. Thecontainer according to claim 9, wherein the particles trapped in thecoating comprise at least one selected from the group consisting ofcolored pigment particles, mother-of-pearl particles and metallicparticles.
 11. The container according to claims 1, comprising atransparent body, wherein the coating on the inner surface comprises acovalently bonded compound that absorbs radiation in the ultravioletrange.
 12. The container according to claim 11, wherein the covalentlybonded compound that absorbs radiation in the ultraviolet range is abenzophenone.
 13. The container according to claim 11, wherein thecoating present on the inner surface of the container is obtained by aprocess, comprising: (A2) reacting a compound that absorbs radiation inthe ultraviolet range having a reactive functional group R^(r) with asilicon alkoxide of formula (I²):Si(OR)₃R^(c)   (I²) wherein: each is independently an alkyl group; andR^(c) is a functional group which reacts with the functional group R^(r)to form a covalent bond between the compound that absorbs in theultraviolet range and the silicon alkoxide, whereby there is formed asilicon alkoxide of formula (I):Si(OR)₃R¹   (I), wherein R has the meaning given hereinbefore and R′ isa group resulting from the reaction of the functional group R^(c) withthe reactive functional group R^(r); and then (B2) sol-gel coating theinner surface of the container with the silicon alkoxide mineralprecursor (I) obtained in (A2), optionally in association with a siliconalkoxide of formulaSi(OR″)₄ wherein each R″ is, independently, an alkyl group.
 14. Thecontainer according to claim 13, wherein R^(r) is —OH, R^(c) is —C═N═O,and the silicon alkoxide (I¹) is 3-isocyanatopropyltriethoxy-silane:(CH₂H₅O)₃Si—(CH₂)₃—NCO.
 15. The container according to claim 13,wherein, in (B2), the sol-gel coating comprises a mixture of the siliconalkoxide of formula (I) and tetraethoxysilane.
 16. The containeraccording to claim 4, wherein the body of the container is made ofglass.
 17. The container according to claim 1, wherein the container isa vial or a bottle.
 18. A cosmetic package, comprising: a cosmeticcomposition; and the container according to claim 1; wherein thecosmetic composition is contained in the container.
 19. The cosmeticpackage according to claim 18, wherein the cosmetic composition is atleast one selected from the group consisting of a composition in liquidform, a water-based composition, an alcoholic composition and anaqueous-alcoholic composition.